在EB病毒感染的宿主T细胞中PD-1发挥其免疫抑制功能。本项目基于观察到在EBV阳性B淋巴细胞中PD-1基因表达上调、EBNA-1依赖的PD-1甲基化水平下调及EBNA-1分别与DNMT3B蛋白和PD-1启动子序列相互作用的基础上,拟通过EBV感染的外周血B淋巴细胞、LCLJul、BL41细胞模型，采用RNA干扰、基因过表达技术，以PD-1甲基化及其表达、B细胞分化与Ig类转化、细胞因子表达为主要指标，观察PD-1基因甲基化特征及在B细胞中生理功能；以293T和LCLJul为对象，采用染色质免疫共沉淀、Luciferase报告基因和前面提及技术手段，确证EBNA-1/DNMT3B结合到PD-1启动子区并调控其甲基化；以论证在EB病毒感染的B细胞中，EBNA-1/ DNMT3B介导的PD-1甲基化负调控其表达，进而调控其在B细胞中功能的假说；以期探寻治疗EBV 诱发B淋巴瘤新的药物靶点。

PD-1 play an important role of immunosurppession in T cells from the Epstein-Barr virus (EBV)infected individual.Based on the data that the expression of PD-1 gene in EBV positive B cells was upregulated,EBNA-1 dependant methylation downregulated,and on the observation of the physical interaction between EBNA-1 and DNMT3B protein(IP) ,and EBNA-1 on the PD-1 promoter(CHIP),we hypothesize that EBNA-1/DNMT3B mediated PD-1 methylation negatively regulates PD-1 gene expression, and thereby further impacts on the immune response of EBV infected B cells.We propose to analyze PD-1 methylation and expression,B cell differentiation and Ig change,production of B cell-derived factors in EBV infected primary B cells and LCLJul,BL41 cells, via RNA interference,gene overexpression and use of inhibitors of methylation transferases in order to gain a better understanding of PD-1 methylation and its physiological functions. We will further investigate the EBNA-1/DNMT3B binding to the promoter of PD-1 and regulation of its methylation in 293T and LCLJul cell lines through chromatin immunoprecipitation, Luciferase reporter technique and techniques stated above. Those efforts may reveal novel targets for drug development in the treatment of EBV-related B lymphomas.